Dichlorodiphenyltrichloroethane And Metabolites Research Articles

Biological, Chemical, and Ecotoxicological Assessments Using Benthos Provide Different and Complementary Measures of Lake Ecological Status

The Water Framework Directive (WFD) aims to monitor continental water bodies in Europe to achieve good ecological status. Indexes based on biological quality elements (BQEs), ecotoxicological tests, and chemical characterizations are commonly used with standardized protocols to assess sediment quality and the associated risks. Here, we compare the results of quality assessment of benthic macroinvertebrates as BQEs as required by the WFD with the results of ecotoxicological tests and assessment of selected persistent organic pollutants (POPs) in sediments of the same eight water bodies in Italy. The aim was to verify if the assessment of quality through macroinvertebrates through POPs analyses and ecotoxicological tools can yield comparable, overlapping, or complementary results. We used the Benthic Quality Index (BQIES) for macroinvertebrates (two different applications), legacy POPs (dichloro-diphenyl-trichloroethane and metabolites (DDTs) and polychlorinated-biphenyls (PCBs)), and the emergence ratio (ER) and development rate (DR) for ecotoxicology. The results showed that the two indices within each approach were highly correlated, but between approaches, each result can lead to a completely different scenario, with rather different results of the assessment of ecosystem quality. The most striking result was that very few significant correlations existed between sediment quality assessment through macroinvertebrates and the risk assessment through analyses of micropollutants and ecotoxicological tests. The highest absolute r-value (0.81) was for the correlation between the BQIESbottom index and PCBs for micropollutants, whereas all other pairwise comparisons between indices had r-values ranging between 0.07 and 0.53. Our analysis calls for a caveat in the blind application of one or only a few indices of water/sediment quality, as the results of a single index may not represent the complexity of a freshwater ecosystem.

Organochlorine pesticides exposure may disturb homocysteine metabolism in pregnant women

Maternal exposure to organochlorine pesticides (OCPs) has an adverse impact on maternal and fetal health, and excessive homocysteine is related to a variety of adverse pregnancy outcomes. Biomimetic studies suggest that OCPs interfere with folate-dependent pathways, but little evidence is available from studies with human subjects. This study explored whether exposure to OCPs interferes with the metabolism of homocysteine, which is folate dependent. A total of 313 pregnant women at 12–20 weeks gestation were recruited in Shanxi province, China, from 2014 to 2015. Plasma concentrations of 20 OCPs, including dichlorodiphenyltrichloroethane and metabolites (DDTs), hexachlorobenzene (HCB), and hexachlorocyclohexanes (HCHs), were analyzed by gas chromatography–mass spectrometry. Blood folate concentrations were analyzed by microbiological assay, and plasma homocysteine concentrations were determined by enzyme-linked immunosorbent assay. Information on demographics, lifestyle behaviors, and folic acid supplementation was collected by in-person interview. Of the women, 99% reported having taken folic acid supplements. Results of a logistic regression analysis showed that higher plasma levels of OCPs were associated with increased odds of higher plasma homocysteine after adjustment for potential confounding factors. Positive correlations were observed between plasma OCPs and plasma homocysteine concentrations: HCB (r = 0.176, p = 0.002), β-HCH (r = 0.172, p = 0.002), ρ,ρ′-DDE (r = 0.132, p = 0.020), ρ,ρ′-DDD (r = 0.161, p = 0.004), and ο,ρ′-DDT (r = 0.144, p = 0.011). Plasma concentrations of OCPs were negatively correlated with red blood cell (RBC) folate in the low-RBC-folate subgroup, but the correlations were not statistically significant. A positive correlation was observed between OCPs and homocysteine in the low-RBC-folate subgroup. These findings suggest that OCPs may disturb the folate-dependent homocysteine metabolism pathway.

Occurrence of organochlorine compounds in fish from freshwater environments of the central Andes, Argentina.

The Central Andes region is considered an area of high environmental relevance in South America and it is rich in glaciers, which are the main fresh water sources and reservoirs of the region. The presence of organochlorine compounds (OCs) is an environmental threat due to their persistence and adverse effects on wildlife and humans. The levels of OCs, such as chlordane compounds (CHLs), dichlorodiphenyltrichloroethane and metabolites (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), and polychlorinated biphenyls (PCBs), were determined in muscle and liver tissues of fish and in sediments collected from different sites of the central Andes: the Mendoza River and the Yaucha River (rainbow trout: Oncorhynchus mykiss) and Carrizal Dam (silverside: Odontesthes bonariensis). Regardless of studied site and fish tissue, the general OC trend was: DDTs > PCBs > HCHs > CHLs > HCB. The results showed clear geographic distribution patterns for DDTs. Among the sampling sites, silverside fish showed the highest average load of DDTs (614 and 867 ng g-1 lw in muscle and liver tissues, respectively). Based on the biota-sediment bioaccumulation factor (BSAF), both rainbow trout and silverside fish showed comparable capability to accumulate p,p'-DDT in their tissues. Intraspecific correlational analysis showed that CB-138 in muscle and p,p'-DDT in liver were clearly correlated with the lipid content in silverside specimens, which highlights the relevance of taking into account the fat content and the type of target tissues.

Assessment of seasonal variations in persistent organic pollutants across the region of Tuscany using passive air samplers

Concentrations of persistent organic pollutants (POPs) were measured for an entire year in the region of Tuscany, Italy. Passive air samplers consisting of polyurethane foam (PUF) disks were deployed over four sampling periods of 3–5 months from April 2008 to July 2009 in urban (n = 6) and rural (n = 4) sites. The aim of the study was to characterize the spatial and seasonal variations in selected POPs. The POP concentrations (pg m−3) in the air were dominated by dichlorodiphenyltrichloroethane and metabolites (DDTs) and polychlorinated biphenyls (∑7PCBs). DDTs, and ∑7PCBs showed a clear decreasing urban > rural gradient. The concentrations of DDTs and PCBs were up to 10 and 6 times higher, respectively, in urban sites than in rural sites. ∑7PCBs showed a significant correlation with the urbanized areas located <5 km around the sampling sites. For hexachlorocyclohexanes (HCHs), α-HCH concentrations were similar at both sampling sites and were found to be quite uniform during the four sampling periods. Seasonal fluctuations were observed for DDTs, and ∑7PCBs, with the highest concentrations observed during period 4 (summer–spring); this is most likely due to a temperature-driven re-emission from local sources. These findings were also supported by an air back trajectory analysis in the study area. This study contributes new information about POP levels in the Italian atmosphere and demonstrates the feasibility of using PUF disks to simultaneously assess seasonal concentrations at different sampling sites.

Bioaccumulation of organochlorine pesticides in the liver of birds from Boraphet wetland, Thailand

The accumulation of toxic and persistent organochlorine pesticides (OCPs) in the liver tissues of nine species of birds collected from the wetland, Bueng Boraphet, central Thailand was studied during April 2007 to September 2010. Contamination at different trophic levels (in carnivorous, omnivorous, and insectivorous birds) was also analysed. The study indicates that birds in the Boraphet wetland are still subject to OCP contamination. Total dichlorodiphenyltrichloroethane and metabolites ( DDTs) and total aldrin ( ALD) accumulated the most, followed successively by total hexachlorocyclohexanes ( HCH) and total chlordane compounds ( CHL). Carnivorous birds were at highest risk of contamination by OCPs due to their highest trophic level. Omnivorous birds were contaminated with moderate levels of ALD and HCH. The insecticide usage seems to be well managed, as insectivorous birds were the least contaminated, with only low concentrations of ALD and HCH. Regular monitoring of OCP contamination is recommended due to a continued usage of OCPs in agriculture around the Boraphet wetland.

Distribution of organochlorine pesticides in soils of Dashiwei Karst Tiankeng (giant doline) area in South China

Surface soil samples were collected in two karst Tiankengs, Dashiwei and Datuo, situated within the Dashiwei Tiankeng group, located in Leye County of Guangxi province, South China. The soil samples were analyzed for 23 kinds of organochlorine pesticides (OCPs) using a gas chromatography electron capture detector device. The results showed that the concentrations of OCPs in soils of Dashiwei Tiankeng ranged from 0.03 to 5.13 ng/g for total OCPs, not detectable (ND) to 0.22 ng/g for Hexachlorocyclohexane (HCHs), and 0.01 to 3.61 ng/g for Dichlorodiphenyltrichloroethane and metabolites (DDTs). Concentration of the total OCPs in soils of Datuo Tiankeng ranged from 0.13 to 14.36 ng/g, ND to 0.39 ng/g for HCHs, and 0.01 to 3.28 ng/g for DDTs. These concentrations indicated that there could be new inputs of HCHs and DDTs from recent application of lindane and dicofol in this area. Further analysis also revealed that the concentration of OCPs at the bottom of both Tiankengs was higher than the top. The variability in concentrations between the top and the bottom was attributed to the “cold trapping effect” for persistent organic pollutants (POPs) in karst Tiankeng topography. The difference in temperature between the top and bottom of Tiankeng is a predominating factor which can cause a POPs “cold trapping effect.” Other environmental factors are proposed to explain the difference in concentration such as humidity, topography (or slope), wind speed, wind direction, solar radiation, vegetation cover, and soil organic matter. The environmental condition of Dashiwei Tiankeng appears to favor the accumulation of OCPs than that of Datuo Tiankeng because Dashiwei Tiankeng is a matured Tiankeng but Datuo Tiankeng is a degraded one. Thus, there is the need for further studies on the environmental factors influencing distribution of OCPs in karst Tiankeng.

Residues of HCHs and DDTs in Soils and Sediments of Preconstructing Urban Wetland

Residues of hexachlorohexanes isomers (HCHs) and dichlorodiphenyltrichloroethane and metabolites (DDTs) in the soils and sediments of Dayanghan Wetland in Wuhu, China were investigated. The concentrations of ΣHCH in soils and sediments averaged 1.35 and 3.77μg/kg with the predominance of β-HCH and δ-HCH, respectively. The concentrations of ΣDDT in soils and sediments averaged of 7.80 and 2.80μg/kg, respectively, with the dominance of o, p'-DDT. The concentrations of HCHs in the soils and sediments and DDTs in the sediments were categorized as no pollution, but the level of DDTs in the soils was classified as low pollution.

Occurrence of organochlorine pesticide residues in eggs, chicken and meat in Jordan

Organochlorine pesticide (OCP) residues in 519 samples; comprising eggs, chicken and meat (lamb and beef), collected from Jordan were determined. All samples were analyzed for their residual contents of aldrin, dichlorodiphenyltrichloroethane and metabolites (DDTs), dieldrin, endosulfan isomers, endrin, hexachlorocyclohexane isomers (HCHs), heptachlor, heptachlor epoxide and hexachlorobenzene (HCB). The samples were Soxhlet extracted for 8 h in 250 mL petroleum ether. The cleanup of the samples was performed by Florisil column chromatography and analysis was done on a gas chromatography equipped with an electron capture detector (GC-ECD). The results indicated that 28% (38/134), 20% (23/115) and 49% (131/270) of the examined eggs, chicken and meat samples, respectively, were contaminated with OCP residues. HCHs and DDTs are the most prominently noticed compounds, as they were detected at a high incidence. On the other hand, heptachlor, heptachlor epoxide, HCB, aldrin and endrin compounds were only present in less than 7% of the analyzed samples. These residues are present despite complete ban on the use of OCPs for agricultural purposes in Jordan. No residues of op′-DDD, op′-DDT, dieldrin, α-endosulfan and β-endosulfan were detected.

Organochlorine pesticide residuals in chickens and eggs at a poultry farm in Beijing, China

Chicken organs, animal feed, droppings, and ambient air were sampled at a farm in Beijing to determine the concentrations of hexachlorocyclohexane isomers (HCHs) and dichlorodiphenyltrichloroethane and metabolites (DDTs). Mean fresh weight concentrations of HCHs and DDTs were 0.122 ± 0.061 ng/g and 0.051 ± 0.038 ng/g in the muscles. These values are 1–2 orders of magnitude lower than those reported in China in 1980. Contaminated feed was the main source of HCHs and DDTs. Only 12.8% of HCH and 3.3% of DDT of the amount consumed were excreted. Accumulated quantities of HCHs and DDTs increased during growth. However, concentrations of HCHs and DDTs did not increase because of dilution from rapid growth. Based on the observed residual levels in mature chicken and the average diet of residents of China, the contributions from chicken and egg consumption to per capita daily intake of HCHs and DDTs were 487% and 88% of those of fish consumption.

Validation of Dietary Intake of Dichlorodiphenyltrichloroethane and Metabolites in Two Populations from Beijing and Shenyang, China Based on the Residuals in Human Milk

This paper presents the results of an investigation on association between dietary intakes and human milk concentrations of dichlorodiphenyltrichloroethane and metabolites (DDTs) of two populations from Beijing and Shenyang, China. We analyzed human milk samples from 76 women and 287 composite food samples covering major food categories for concentrations of DDTs. We also collected information on food consumptions and calculated dietary intakes of DDTs of the participants on individual basis. The median values of the measured DDTs in human milk were 125 ng/g lipid and 132 ng/g lipid for the samples from Beijing and Shenyang, respectively. The mean (+/-standard deviation) daily dietary intakes of DDTs by the two groups were 32.0 +/- 14.2 ng/kg day and 27.9 +/- 11.3 ng/kg day, respectively. The temporal trends of decreasing in DDTs and increasing in DDE/DDT ratio suggested that the residuals were primarily from historical application. We found a significant correlation between human milk concentration and daily dietary intake of DDTs, while the dietary intake could explain 22% of the variation in the DDTs in human milk. In addition to dietary exposure, we also found that maternal body mass index (body weight divided by the squared height), body weight, body height, and mother's age contributed significantly to the variation of DDTs in human milk after intake normalization. The result of a probabilistic risk assessment indicated that the exposure of infants to DDTs through breast feeding would be a public health concern for years to come, although breast feeding is still recommended.

Is external contamination with organic pollutants important for concentrations measured in bird feathers?

Although there is increasing evidence that bird feathers can be used as a non-destructive biomonitoring tool for organic pollutants [such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and p,p′-dichlorodiphenyl-trichloroethane and metabolites (DDTs)], the importance of external contamination of these organic pollutants onto the feathers has not been considered. Here we examine to which extent external contamination of organic pollutants occurs onto the feathers of a predatory bird. We have analysed primary wing feathers of 16 common buzzards ( Buteo buteo) collected in Belgium. In order to study differences in external contamination within and among wing feathers, the vane and the shaft of each feather were separated and were analysed in parallel, pooled for the three inner and the three outer primary wing feathers. Most organic pollutants could be measured in these pooled samples of both the vane and the shaft. Concentrations of hexachlorobenzene (HCB), DDTs, PCBs and PBDEs were significantly higher in the vane compared to the shaft. The profiles of PCBs and PBDEs in the shaft closely resembled the profiles in liver and muscle tissue, in contrast with the profile of the vane. The PBDE congeners 47, 99 and 153 had a similar contribution in shafts of primary feathers of common buzzards. Although these results suggest that external contamination could be important on the vane, no differences in the profile of PBDEs or PCBs were found between the inner and outer (more exposed) primary feathers. Furthermore, correlation coefficients with internal tissues were not univocally distinct between the shaft and the vane. Therefore our results indicate that the higher concentrations found in the vane in comparison to the shaft do not originate from external contamination via the air, but that other factors such as structure and chemical properties of the feathers may be of importance. The lack of significant external contamination onto the feather surface is an additional asset for the use of feathers as a non-destructive biomonitor for organic pollutants.

Historical trends in persistent organic pollutants and metals recorded in sediment from Lake Ellasjøen, Bjørnøya, Norwegian Arctic

Ellasjøen receives contaminants from both atmospheric and biological transport (seabird guano). Historical trends of selected persistent organic pollutants and metals were determined by interpretation of down-core contaminant profiles in conjunction with sediment layer ages, determined by the 210Pb method. Polychlorinated biphenyls (PCBs) and dichloro-diphenyl-trichloroethane and metabolites (DDTs) increased from about 1930 until 1970 (max. sum PCBs 71.8 ng/g dry weight (dw), max sum DDTs 4.0 ng/g dw), declining afterwards to 46.4 ng/g dw and 1.6 ng/g dw, respectively. Polybrominated diphenylethers (PBDEs) concentrations are increasing in Ellasjøen, reaching 0.73 ng/g dw in 2001. Hexabromocyclododekane (HBCD) was measured only in sediment from 1–2 cm depth (0.43 and 3.88 ng/g dw of α- and γ-HBCD, respectively). Most metals (As, Cd, Co, Ni and Zn) showed a similar pattern as PCBs. No clear trends were observed for Cr, Pb or V. Mercury (Hg) has increased gradually since the beginning of the industrial era.

Contents and sources of polycyclic aromatic hydrocarbons and organochlorine pesticides in vegetable soils of Guangzhou, China

We investigated contents, distribution and possible sources of PAHs and organochlorine pesticides (Ops) in 43 surface and subsurface soils around the urban Guangzhou where variable kinds of vegetables are grown. The results indicate that the contents of PAHs (16 US EPA priority PAHs) range from 42 to 3077 μg/kg and the pollution extent is classified as a moderate level in comparison with other investigations and soil quality standards. The ratios of methylphenanthrenes to phenanthrene(MP/P), anthracene to anthracene plus phenanthrene (An/178), benz[ a]anthracene to benz[ a]anthracene plus chrysene (BaA/228), indeno[1,2,3- cd]pyrene to indeno[1,2,3- cd]pyrene plus benzo[ ghi]perylene (In/In + BP) suggest that the sources of PAHs in the soil samples are mixed with a dominant contribution from petroleum and combustion of fossil fuel. The correlation analysis shows that the PAHs contents are significantly related to total organic carbon contents (TOC) ( R 2 = 0.75) and black carbon contents (BC) ( R 2 = 0.62) in the soil samples. Dichlorodiphenyltrichloroethane and metabolites (DDTs) and hexachlorocyclohexanes and metabolites (HCHs) account largely for the contaminants of OPs. The concentrations of DDTs range from 3.58 to 831 μg/kg and the ratios for DDT/(DDD + DDE) are higher than 2 in some soil samples, suggesting that DDT contamination still exists and may be caused by its persistence in soils and/or impurity in the pesticide dicofol. The concentrations of HCHs are 0.19–42.3 μg/kg.

Levels, persistence and bioavailability of organic contaminants present in marine harbor sediments impacted by raw sewage

As part of a program to investigate the levels, fate and bioaccumulation of organic contaminants in a polluted marine harbor, organochlorine compounds including the polychlorinated biphenyls (PCBs), dichloro diphenyltrichloroethane and metabolites (DDTs), chlordanes, dibenzo-p dioxins (Ds) and dibenzofurans (Fs), polycyclic aromatic hydrocarbons (PAHs) and sulphur hetero cycles were analysed in sediments spiked with St. John's Harbor sludge. Winter flounder ( Pseudopleuronectes americanus) were exposed to these sediments containing six levels of harbor sludge during four winter months. Following exposure, sediments were reanalysed to investigate the persistence of the contaminants. The primary contaminants detected were PAHs (∼5000 ng/g), predominantly alkylated phenanthrenes, fluoranthene and pyrene; PCBs with a predominance of Aroclor 1260 signature (∼64 ng/g), DDTs (∼5 ng/g), hepta and octachloro dioxins and furans (∼0.5 ng/g) with very low levels of less chlorinated congeners. The PAHs degraded with an estimated half life of 2 to 3 months, while no significant degradation could be attributed to the other compounds. Bioaccumulation to muscle showed the potential uptake of contaminants in biota inhabiting the harbor. A dose-response relationship was observed between spiked sediments and the concentrations of PCB congener 153 and unresolved congeners 138/163/164 in muscle. Of the dioxins and furans, only 2, 3, 7, 8-tetrachlorofuran was detectable in muscle and at a similar concentration in all exposures indicating a similar bioavailability independent of the fraction of sludge in sediments. Of the PAHs, only naphthalene and methyl naphthalenes were detected in muscle, but did not display a dose-response. One bile metabolite of pyrene was quantified and demonstrates metabolism. Biota-sediment accumulation factors were of 0.2 to 7 indicating that equilibrium was approached, with the exception of the hepta and octachloro dioxins and furans which were not significantly bioaccumulated.

Organochlorine pesticide residues in buffaloe and cattle fat in Assiut Governorate

Organochlorine pesticide (OCP) residues in 519 samples; comprising eggs, chicken and meat (lamb and beef), collected from Jordan were determined. All samples were analyzed for their residual contents of aldrin, dichlorodiphenyltrichloroethane and metabolites (DDTs), dieldrin, endosulfan isomers, endrin, hexachlorocyclohexane isomers (HCHs), heptachlor, heptachlor epoxide and hexachlorobenzene (HCB). The samples were Soxhlet extracted for 8 h in 250 mL petroleum ether. The cleanup of the samples was performed by Florisil column chromatography and analysis was done on a gas chromatography equipped with an electron capture detector (GC-ECD). The results indicated that 28% (38/134), 20% (23/115) and 49% (131/270) of the examined eggs, chicken and meat samples, respectively, were contaminated with OCP residues. HCHs and DDTs are the most prominently noticed compounds, as they were detected at a high incidence. On the other hand, heptachlor, heptachlor epoxide, HCB, aldrin and endrin compounds were only present in less than 7% of the analyzed samples. These residues are present despite complete ban on the use of OCPs for agricultural purposes in Jordan. No residues of op′-DDD, op′-DDT, dieldrin, α-endosulfan and β-endosulfan were detected.

Organochlorine Pesticides, PBBs, And Mercury in Round Whitefish Fillets from Saginaw Bay, Lake Huron, 1977–1978

Successful development of a commercial, small-mesh trap net fishery for round whitefish ( Prosopium cylindraceum) in Saginaw Bay, Lake Huron, prompted analysis of round whitefish fillets for selected contaminants [dieldrin, dichlorodiphenyl trichloroethane and metabolites (DDT), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), chlordane, methyl mercury, and total mercury] to determine the fish's suitability for human consumption. Concentrations of all contaminants measured in 1977–1978 were below U. S. Food and Drug Administration action guidelines for fish; PBBs were below detection limits (0.001 mg/kg) for all fillets analyzed. Only PCBs and total DDT residues displayed a strong direct relationship with fish length. Fillets from males consistently exhibited higher mean concentrations of contaminants than did females. No changes in contaminant levels with season were observed.